Attraction: Rio Camuy Cave Park

When sunlight streams into the entryway of these caves, formed by the Camuy River more than one million years ago, a spotlight shines on one of nature's most exquisite wonders.

A network of caves laces through the 260-acre park, only some of which is open to the public. Take the trolley down to a sinkhole lush with plants and fish, or admire the stalagmites and stalactites that protrude from Cueva Clara's walls like icy daggers. Spiral Sinkhole and Cave is for experienced spelunkers only—205 daunting steps lead down to the grotto.